Sports training devices specifically associated with racket-based sports such as tennis, racket ball squash or badminton include fixed weights added to the racket, used to enhance swing training performance, to increase strength, or to warm up prior to game play. For example, U.S. Pat. No. 3,330,560 to Higdon defines flexible weight holders with pockets that attach to the top of the racket. U.S. Pat. No. 4,000,893 to Evans, U.S. Pat. No. 4,052,061 to Stewart, U.S. Pat. No. 4,142,721 to Faleck et al and U.S. Pat. No. 4,538,812 to Mugford all present variations of designs that connect a weight or multiple weights to the throat of the racket. However, many of these slip and move on or against the racket when swung. Similarly, U.S. Pat. No. 4,671,150 to Schoenwetter presents a weighted racket cover that fits loosely over the strings, allowing it to slap back and forth hitting the strings when used.
U.S. Pat. No. 4,200,285 to Petitti Jr. and U.S. Pat. No. 5,083,777 to Held present designs that connect to the edges of the racket. The weights are on opposing edges of the racket and can be difficult to adjust and balance to achieve the desired swing and warm up performance.
U.S. Pat. No. 5,286,021 to Shaw is a weighted device that connects to the lower end of the racket head, but not the strings. U.S. Pat. No. 4,249,728 to Bratt defines a tennis racket exercise weight assembly consisting of opposing fixed weights attached directly to the strings, but having limited utility. Likewise U.S. Pat. No. 5,944,622 to Brett et al. presents a molded device with a pair of opposing shells each including a grid of nub projection fingers that are specifically designed to grab and hold the strings, but again with limited utility. U.S. Pat. No. 5,964,671 to Edwards et al presents a system consisting of two similar opposing parts that screw or clamp together over the strings, with a gasket next to the strings. This system suggests that the each part contain cavities for the weights, with a plurality of one or more removable weights that attach directly to the strings. In actual use, the two similar parts can be difficult to install on the racket, especially if there are multiple removable weights and gasket pieces. In addition, the gasket material when used on both sides of the strings tends to bind, making the removal of the weight system difficult.
There is, therefore, a need in the art for an improved weight for racket-based sports training.